As the subject line says it works fine in IE and Chrome..
but nothing happens in Firefox.
From my testing the problem seems to be occuring
when using jquery to open the xml feed.
(I have not edited jquery at all and I'm using version 1.2.6)

// IF filename is a local link then replace filename with self referencing javascript call
if (is_javascript == 0)
{

//need to pull doc_name and the summary_id and replace the function name and send these to it.
//needs to look like this javascript:XMLSummary('xml_files/data2.xml','Mission Verbs')
//the summary_id eg in this case '2' should match up with the xml file number